ceph_filestore_tool: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/ceph_filestore_tool - from package: ceph-test

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/ceph/bin/ceph_filestore_tool - from package: ceph-test

You may install the required package with command apt-get install {package}
Error in other languages:
ceph_filestore_tool: bevel nie gevind nie
ceph_filestore_tool: comandă negăsită
ceph_filestore_tool: comando não encontrado
ceph_filestore_tool: commande introuvable
ceph_filestore_tool: command not found
ceph_filestore_tool: käsku ei ole
ceph_filestore_tool: không tìm thấy lệnh
ceph_filestore_tool: komanda nerasta
ceph_filestore_tool: Kommando nicht gefunden.
ceph_filestore_tool: kommandot finns inte
ceph_filestore_tool: komut yok
ceph_filestore_tool: nie znaleziono polecenia
ceph_filestore_tool: níor aimsíodh an t-ordú
ceph_filestore_tool: no se encontró la orden
ceph_filestore_tool: no s'ha trobat l'ordre
ceph_filestore_tool: opdracht niet gevonden
ceph_filestore_tool: parancs nem található
ceph_filestore_tool: perintah tidak ditemukan
ceph_filestore_tool: príkaz nenájdený
ceph_filestore_tool: příkaz nenalezen
ceph_filestore_tool: команда не найдена
ceph_filestore_tool: командата не е открита
ceph_filestore_tool: 命令找不到
ceph_filestore_tool: コマンドが見つかりません